In an experiment, the US Department of Homeland Security (DHS) is deploying radio frequency identification (RFID) technology to track immigrants entering and exiting the country, according to a Hindu Business Line report. The RFID is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. Beginning July 31, the experiment applies to people without green cards entering the US with a visa to work, study or tour. Over the next year, people in these categories will be issued new "I-94" visa cards embedded with an RFID tag at five border crossings of Nogales East and Nogales West in Arizona, Alexandria Bay in New York, and the Pacific Highway and Peace Arch in Washington.